// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/compiler/machine-operator-reducer.h"
#include <cmath>

#include "src/base/bits.h"
#include "src/base/division-by-constant.h"
#include "src/base/ieee754.h"
#include "src/base/overflowing-math.h"
#include "src/compiler/diamond.h"
#include "src/compiler/graph.h"
#include "src/compiler/machine-graph.h"
#include "src/compiler/node-matchers.h"
#include "src/compiler/node-properties.h"
#include "src/conversions-inl.h"

namespace v8 {
namespace internal {
    namespace compiler {

        MachineOperatorReducer::MachineOperatorReducer(Editor* editor,
            MachineGraph* mcgraph,
            bool allow_signalling_nan)
            : AdvancedReducer(editor)
            , mcgraph_(mcgraph)
            , allow_signalling_nan_(allow_signalling_nan)
        {
        }

        MachineOperatorReducer::~MachineOperatorReducer() = default;

        Node* MachineOperatorReducer::Float32Constant(volatile float value)
        {
            return graph()->NewNode(common()->Float32Constant(value));
        }

        Node* MachineOperatorReducer::Float64Constant(volatile double value)
        {
            return mcgraph()->Float64Constant(value);
        }

        Node* MachineOperatorReducer::Int32Constant(int32_t value)
        {
            return mcgraph()->Int32Constant(value);
        }

        Node* MachineOperatorReducer::Int64Constant(int64_t value)
        {
            return graph()->NewNode(common()->Int64Constant(value));
        }

        Node* MachineOperatorReducer::Float64Mul(Node* lhs, Node* rhs)
        {
            return graph()->NewNode(machine()->Float64Mul(), lhs, rhs);
        }

        Node* MachineOperatorReducer::Float64PowHalf(Node* value)
        {
            value = graph()->NewNode(machine()->Float64Add(), Float64Constant(0.0), value);
            Diamond d(graph(), common(),
                graph()->NewNode(machine()->Float64LessThanOrEqual(), value,
                    Float64Constant(-V8_INFINITY)),
                BranchHint::kFalse);
            return d.Phi(MachineRepresentation::kFloat64, Float64Constant(V8_INFINITY),
                graph()->NewNode(machine()->Float64Sqrt(), value));
        }

        Node* MachineOperatorReducer::Word32And(Node* lhs, Node* rhs)
        {
            Node* const node = graph()->NewNode(machine()->Word32And(), lhs, rhs);
            Reduction const reduction = ReduceWord32And(node);
            return reduction.Changed() ? reduction.replacement() : node;
        }

        Node* MachineOperatorReducer::Word32Sar(Node* lhs, uint32_t rhs)
        {
            if (rhs == 0)
                return lhs;
            return graph()->NewNode(machine()->Word32Sar(), lhs, Uint32Constant(rhs));
        }

        Node* MachineOperatorReducer::Word32Shr(Node* lhs, uint32_t rhs)
        {
            if (rhs == 0)
                return lhs;
            return graph()->NewNode(machine()->Word32Shr(), lhs, Uint32Constant(rhs));
        }

        Node* MachineOperatorReducer::Word32Equal(Node* lhs, Node* rhs)
        {
            return graph()->NewNode(machine()->Word32Equal(), lhs, rhs);
        }

        Node* MachineOperatorReducer::Int32Add(Node* lhs, Node* rhs)
        {
            Node* const node = graph()->NewNode(machine()->Int32Add(), lhs, rhs);
            Reduction const reduction = ReduceInt32Add(node);
            return reduction.Changed() ? reduction.replacement() : node;
        }

        Node* MachineOperatorReducer::Int32Sub(Node* lhs, Node* rhs)
        {
            Node* const node = graph()->NewNode(machine()->Int32Sub(), lhs, rhs);
            Reduction const reduction = ReduceInt32Sub(node);
            return reduction.Changed() ? reduction.replacement() : node;
        }

        Node* MachineOperatorReducer::Int32Mul(Node* lhs, Node* rhs)
        {
            return graph()->NewNode(machine()->Int32Mul(), lhs, rhs);
        }

        Node* MachineOperatorReducer::Int32Div(Node* dividend, int32_t divisor)
        {
            DCHECK_NE(0, divisor);
            DCHECK_NE(std::numeric_limits<int32_t>::min(), divisor);
            base::MagicNumbersForDivision<uint32_t> const mag = base::SignedDivisionByConstant(bit_cast<uint32_t>(divisor));
            Node* quotient = graph()->NewNode(machine()->Int32MulHigh(), dividend,
                Uint32Constant(mag.multiplier));
            if (divisor > 0 && bit_cast<int32_t>(mag.multiplier) < 0) {
                quotient = Int32Add(quotient, dividend);
            } else if (divisor < 0 && bit_cast<int32_t>(mag.multiplier) > 0) {
                quotient = Int32Sub(quotient, dividend);
            }
            return Int32Add(Word32Sar(quotient, mag.shift), Word32Shr(dividend, 31));
        }

        Node* MachineOperatorReducer::Uint32Div(Node* dividend, uint32_t divisor)
        {
            DCHECK_LT(0u, divisor);
            // If the divisor is even, we can avoid using the expensive fixup by shifting
            // the dividend upfront.
            unsigned const shift = base::bits::CountTrailingZeros(divisor);
            dividend = Word32Shr(dividend, shift);
            divisor >>= shift;
            // Compute the magic number for the (shifted) divisor.
            base::MagicNumbersForDivision<uint32_t> const mag = base::UnsignedDivisionByConstant(divisor, shift);
            Node* quotient = graph()->NewNode(machine()->Uint32MulHigh(), dividend,
                Uint32Constant(mag.multiplier));
            if (mag.add) {
                DCHECK_LE(1u, mag.shift);
                quotient = Word32Shr(
                    Int32Add(Word32Shr(Int32Sub(dividend, quotient), 1), quotient),
                    mag.shift - 1);
            } else {
                quotient = Word32Shr(quotient, mag.shift);
            }
            return quotient;
        }

        // Perform constant folding and strength reduction on machine operators.
        Reduction MachineOperatorReducer::Reduce(Node* node)
        {
            switch (node->opcode()) {
            case IrOpcode::kProjection:
                return ReduceProjection(ProjectionIndexOf(node->op()), node->InputAt(0));
            case IrOpcode::kWord32And:
                return ReduceWord32And(node);
            case IrOpcode::kWord32Or:
                return ReduceWord32Or(node);
            case IrOpcode::kWord32Xor:
                return ReduceWord32Xor(node);
            case IrOpcode::kWord32Shl:
                return ReduceWord32Shl(node);
            case IrOpcode::kWord64Shl:
                return ReduceWord64Shl(node);
            case IrOpcode::kWord32Shr:
                return ReduceWord32Shr(node);
            case IrOpcode::kWord64Shr:
                return ReduceWord64Shr(node);
            case IrOpcode::kWord32Sar:
                return ReduceWord32Sar(node);
            case IrOpcode::kWord64Sar:
                return ReduceWord64Sar(node);
            case IrOpcode::kWord32Ror: {
                Int32BinopMatcher m(node);
                if (m.right().Is(0))
                    return Replace(m.left().node()); // x ror 0 => x
                if (m.IsFoldable()) { // K ror K => K
                    return ReplaceInt32(base::bits::RotateRight32(m.left().Value(),
                        m.right().Value() & 31));
                }
                break;
            }
            case IrOpcode::kWord32Equal: {
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) { // K == K => K
                    return ReplaceBool(m.left().Value() == m.right().Value());
                }
                if (m.left().IsInt32Sub() && m.right().Is(0)) { // x - y == 0 => x == y
                    Int32BinopMatcher msub(m.left().node());
                    node->ReplaceInput(0, msub.left().node());
                    node->ReplaceInput(1, msub.right().node());
                    return Changed(node);
                }
                // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
                if (m.LeftEqualsRight())
                    return ReplaceBool(true); // x == x => true
                break;
            }
            case IrOpcode::kWord64Equal: {
                Int64BinopMatcher m(node);
                if (m.IsFoldable()) { // K == K => K
                    return ReplaceBool(m.left().Value() == m.right().Value());
                }
                if (m.left().IsInt64Sub() && m.right().Is(0)) { // x - y == 0 => x == y
                    Int64BinopMatcher msub(m.left().node());
                    node->ReplaceInput(0, msub.left().node());
                    node->ReplaceInput(1, msub.right().node());
                    return Changed(node);
                }
                // TODO(turbofan): fold HeapConstant, ExternalReference, pointer compares
                if (m.LeftEqualsRight())
                    return ReplaceBool(true); // x == x => true
                break;
            }
            case IrOpcode::kInt32Add:
                return ReduceInt32Add(node);
            case IrOpcode::kInt64Add:
                return ReduceInt64Add(node);
            case IrOpcode::kInt32Sub:
                return ReduceInt32Sub(node);
            case IrOpcode::kInt64Sub:
                return ReduceInt64Sub(node);
            case IrOpcode::kInt32Mul: {
                Int32BinopMatcher m(node);
                if (m.right().Is(0))
                    return Replace(m.right().node()); // x * 0 => 0
                if (m.right().Is(1))
                    return Replace(m.left().node()); // x * 1 => x
                if (m.IsFoldable()) { // K * K => K
                    return ReplaceInt32(
                        base::MulWithWraparound(m.left().Value(), m.right().Value()));
                }
                if (m.right().Is(-1)) { // x * -1 => 0 - x
                    node->ReplaceInput(0, Int32Constant(0));
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                    return Changed(node);
                }
                if (m.right().IsPowerOf2()) { // x * 2^n => x << n
                    node->ReplaceInput(1, Int32Constant(WhichPowerOf2(m.right().Value())));
                    NodeProperties::ChangeOp(node, machine()->Word32Shl());
                    Reduction reduction = ReduceWord32Shl(node);
                    return reduction.Changed() ? reduction : Changed(node);
                }
                break;
            }
            case IrOpcode::kInt32MulWithOverflow: {
                Int32BinopMatcher m(node);
                if (m.right().Is(2)) {
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Int32AddWithOverflow());
                    return Changed(node);
                }
                if (m.right().Is(-1)) {
                    node->ReplaceInput(0, Int32Constant(0));
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Int32SubWithOverflow());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kInt32Div:
                return ReduceInt32Div(node);
            case IrOpcode::kUint32Div:
                return ReduceUint32Div(node);
            case IrOpcode::kInt32Mod:
                return ReduceInt32Mod(node);
            case IrOpcode::kUint32Mod:
                return ReduceUint32Mod(node);
            case IrOpcode::kInt32LessThan: {
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) { // K < K => K
                    return ReplaceBool(m.left().Value() < m.right().Value());
                }
                if (m.LeftEqualsRight())
                    return ReplaceBool(false); // x < x => false
                if (m.left().IsWord32Or() && m.right().Is(0)) {
                    // (x | K) < 0 => true or (K | x) < 0 => true iff K < 0
                    Int32BinopMatcher mleftmatcher(m.left().node());
                    if (mleftmatcher.left().IsNegative() || mleftmatcher.right().IsNegative()) {
                        return ReplaceBool(true);
                    }
                }
                break;
            }
            case IrOpcode::kInt32LessThanOrEqual: {
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) { // K <= K => K
                    return ReplaceBool(m.left().Value() <= m.right().Value());
                }
                if (m.LeftEqualsRight())
                    return ReplaceBool(true); // x <= x => true
                break;
            }
            case IrOpcode::kUint32LessThan: {
                Uint32BinopMatcher m(node);
                if (m.left().Is(kMaxUInt32))
                    return ReplaceBool(false); // M < x => false
                if (m.right().Is(0))
                    return ReplaceBool(false); // x < 0 => false
                if (m.IsFoldable()) { // K < K => K
                    return ReplaceBool(m.left().Value() < m.right().Value());
                }
                if (m.LeftEqualsRight())
                    return ReplaceBool(false); // x < x => false
                if (m.left().IsWord32Sar() && m.right().HasValue()) {
                    Int32BinopMatcher mleft(m.left().node());
                    if (mleft.right().HasValue()) {
                        // (x >> K) < C => x < (C << K)
                        // when C < (M >> K)
                        const uint32_t c = m.right().Value();
                        const uint32_t k = mleft.right().Value() & 0x1F;
                        if (c < static_cast<uint32_t>(kMaxInt >> k)) {
                            node->ReplaceInput(0, mleft.left().node());
                            node->ReplaceInput(1, Uint32Constant(c << k));
                            return Changed(node);
                        }
                        // TODO(turbofan): else the comparison is always true.
                    }
                }
                break;
            }
            case IrOpcode::kUint32LessThanOrEqual: {
                Uint32BinopMatcher m(node);
                if (m.left().Is(0))
                    return ReplaceBool(true); // 0 <= x => true
                if (m.right().Is(kMaxUInt32))
                    return ReplaceBool(true); // x <= M => true
                if (m.IsFoldable()) { // K <= K => K
                    return ReplaceBool(m.left().Value() <= m.right().Value());
                }
                if (m.LeftEqualsRight())
                    return ReplaceBool(true); // x <= x => true
                break;
            }
            case IrOpcode::kFloat32Sub: {
                Float32BinopMatcher m(node);
                if (allow_signalling_nan_ && m.right().Is(0) && (std::copysign(1.0, m.right().Value()) > 0)) {
                    return Replace(m.left().node()); // x - 0 => x
                }
                if (m.right().IsNaN()) { // x - NaN => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat32(m.right().Value() - m.right().Value());
                }
                if (m.left().IsNaN()) { // NaN - x => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat32(m.left().Value() - m.left().Value());
                }
                if (m.IsFoldable()) { // L - R => (L - R)
                    return ReplaceFloat32(m.left().Value() - m.right().Value());
                }
                if (allow_signalling_nan_ && m.left().IsMinusZero()) {
                    // -0.0 - round_down(-0.0 - R) => round_up(R)
                    if (machine()->Float32RoundUp().IsSupported() && m.right().IsFloat32RoundDown()) {
                        if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat32Sub) {
                            Float32BinopMatcher mright0(m.right().InputAt(0));
                            if (mright0.left().IsMinusZero()) {
                                return Replace(graph()->NewNode(machine()->Float32RoundUp().op(),
                                    mright0.right().node()));
                            }
                        }
                    }
                    // -0.0 - R => -R
                    node->RemoveInput(0);
                    NodeProperties::ChangeOp(node, machine()->Float32Neg());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kFloat64Add: {
                Float64BinopMatcher m(node);
                if (m.IsFoldable()) { // K + K => K
                    return ReplaceFloat64(m.left().Value() + m.right().Value());
                }
                break;
            }
            case IrOpcode::kFloat64Sub: {
                Float64BinopMatcher m(node);
                if (allow_signalling_nan_ && m.right().Is(0) && (Double(m.right().Value()).Sign() > 0)) {
                    return Replace(m.left().node()); // x - 0 => x
                }
                if (m.right().IsNaN()) { // x - NaN => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat64(m.right().Value() - m.right().Value());
                }
                if (m.left().IsNaN()) { // NaN - x => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat64(m.left().Value() - m.left().Value());
                }
                if (m.IsFoldable()) { // L - R => (L - R)
                    return ReplaceFloat64(m.left().Value() - m.right().Value());
                }
                if (allow_signalling_nan_ && m.left().IsMinusZero()) {
                    // -0.0 - round_down(-0.0 - R) => round_up(R)
                    if (machine()->Float64RoundUp().IsSupported() && m.right().IsFloat64RoundDown()) {
                        if (m.right().InputAt(0)->opcode() == IrOpcode::kFloat64Sub) {
                            Float64BinopMatcher mright0(m.right().InputAt(0));
                            if (mright0.left().IsMinusZero()) {
                                return Replace(graph()->NewNode(machine()->Float64RoundUp().op(),
                                    mright0.right().node()));
                            }
                        }
                    }
                    // -0.0 - R => -R
                    node->RemoveInput(0);
                    NodeProperties::ChangeOp(node, machine()->Float64Neg());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kFloat64Mul: {
                Float64BinopMatcher m(node);
                if (allow_signalling_nan_ && m.right().Is(1))
                    return Replace(m.left().node()); // x * 1.0 => x
                if (m.right().Is(-1)) { // x * -1.0 => -0.0 - x
                    node->ReplaceInput(0, Float64Constant(-0.0));
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Float64Sub());
                    return Changed(node);
                }
                if (m.right().IsNaN()) { // x * NaN => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat64(m.right().Value() - m.right().Value());
                }
                if (m.IsFoldable()) { // K * K => K
                    return ReplaceFloat64(m.left().Value() * m.right().Value());
                }
                if (m.right().Is(2)) { // x * 2.0 => x + x
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Float64Add());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kFloat64Div: {
                Float64BinopMatcher m(node);
                if (allow_signalling_nan_ && m.right().Is(1))
                    return Replace(m.left().node()); // x / 1.0 => x
                // TODO(ahaas): We could do x / 1.0 = x if we knew that x is not an sNaN.
                if (m.right().IsNaN()) { // x / NaN => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat64(m.right().Value() - m.right().Value());
                }
                if (m.left().IsNaN()) { // NaN / x => NaN
                    // Do some calculation to make a signalling NaN quiet.
                    return ReplaceFloat64(m.left().Value() - m.left().Value());
                }
                if (m.IsFoldable()) { // K / K => K
                    return ReplaceFloat64(
                        base::Divide(m.left().Value(), m.right().Value()));
                }
                if (allow_signalling_nan_ && m.right().Is(-1)) { // x / -1.0 => -x
                    node->RemoveInput(1);
                    NodeProperties::ChangeOp(node, machine()->Float64Neg());
                    return Changed(node);
                }
                if (m.right().IsNormal() && m.right().IsPositiveOrNegativePowerOf2()) {
                    // All reciprocals of non-denormal powers of two can be represented
                    // exactly, so division by power of two can be reduced to
                    // multiplication by reciprocal, with the same result.
                    node->ReplaceInput(1, Float64Constant(1.0 / m.right().Value()));
                    NodeProperties::ChangeOp(node, machine()->Float64Mul());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kFloat64Mod: {
                Float64BinopMatcher m(node);
                if (m.right().Is(0)) { // x % 0 => NaN
                    return ReplaceFloat64(std::numeric_limits<double>::quiet_NaN());
                }
                if (m.right().IsNaN()) { // x % NaN => NaN
                    return Replace(m.right().node());
                }
                if (m.left().IsNaN()) { // NaN % x => NaN
                    return Replace(m.left().node());
                }
                if (m.IsFoldable()) { // K % K => K
                    return ReplaceFloat64(Modulo(m.left().Value(), m.right().Value()));
                }
                break;
            }
            case IrOpcode::kFloat64Acos: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::acos(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Acosh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::acosh(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Asin: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::asin(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Asinh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::asinh(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Atan: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::atan(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Atanh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::atanh(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Atan2: {
                Float64BinopMatcher m(node);
                if (m.right().IsNaN()) {
                    return Replace(m.right().node());
                }
                if (m.left().IsNaN()) {
                    return Replace(m.left().node());
                }
                if (m.IsFoldable()) {
                    return ReplaceFloat64(
                        base::ieee754::atan2(m.left().Value(), m.right().Value()));
                }
                break;
            }
            case IrOpcode::kFloat64Cbrt: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::cbrt(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Cos: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::cos(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Cosh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::cosh(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Exp: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::exp(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Expm1: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::expm1(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Log: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::log(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Log1p: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::log1p(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Log10: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::log10(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Log2: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::log2(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Pow: {
                Float64BinopMatcher m(node);
                if (m.IsFoldable()) {
                    return ReplaceFloat64(
                        base::ieee754::pow(m.left().Value(), m.right().Value()));
                } else if (m.right().Is(0.0)) { // x ** +-0.0 => 1.0
                    return ReplaceFloat64(1.0);
                } else if (m.right().Is(-2.0)) { // x ** -2.0 => 1 / (x * x)
                    node->ReplaceInput(0, Float64Constant(1.0));
                    node->ReplaceInput(1, Float64Mul(m.left().node(), m.left().node()));
                    NodeProperties::ChangeOp(node, machine()->Float64Div());
                    return Changed(node);
                } else if (m.right().Is(2.0)) { // x ** 2.0 => x * x
                    node->ReplaceInput(1, m.left().node());
                    NodeProperties::ChangeOp(node, machine()->Float64Mul());
                    return Changed(node);
                } else if (m.right().Is(-0.5)) {
                    // x ** 0.5 => 1 / (if x <= -Infinity then Infinity else sqrt(0.0 + x))
                    node->ReplaceInput(0, Float64Constant(1.0));
                    node->ReplaceInput(1, Float64PowHalf(m.left().node()));
                    NodeProperties::ChangeOp(node, machine()->Float64Div());
                    return Changed(node);
                } else if (m.right().Is(0.5)) {
                    // x ** 0.5 => if x <= -Infinity then Infinity else sqrt(0.0 + x)
                    return Replace(Float64PowHalf(m.left().node()));
                }
                break;
            }
            case IrOpcode::kFloat64Sin: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::sin(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Sinh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::sinh(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Tan: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::tan(m.Value()));
                break;
            }
            case IrOpcode::kFloat64Tanh: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(base::ieee754::tanh(m.Value()));
                break;
            }
            case IrOpcode::kChangeFloat32ToFloat64: {
                Float32Matcher m(node->InputAt(0));
                if (m.HasValue()) {
                    if (!allow_signalling_nan_ && /*std::*/isnan(m.Value())) {
                        // Do some calculation to make guarantee the value is a quiet NaN.
                        return ReplaceFloat64(m.Value() + m.Value());
                    }
                    return ReplaceFloat64(m.Value());
                }
                break;
            }
            case IrOpcode::kChangeFloat64ToInt32: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt32(FastD2IChecked(m.Value()));
                if (m.IsChangeInt32ToFloat64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kChangeFloat64ToInt64: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt64(static_cast<int64_t>(m.Value()));
                if (m.IsChangeInt64ToFloat64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kChangeFloat64ToUint32: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt32(FastD2UI(m.Value()));
                if (m.IsChangeUint32ToFloat64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kChangeInt32ToFloat64: {
                Int32Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(FastI2D(m.Value()));
                break;
            }
            case IrOpcode::kChangeInt32ToInt64: {
                Int32Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt64(m.Value());
                break;
            }
            case IrOpcode::kChangeInt64ToFloat64: {
                Int64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(static_cast<double>(m.Value()));
                if (m.IsChangeFloat64ToInt64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kChangeUint32ToFloat64: {
                Uint32Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceFloat64(FastUI2D(m.Value()));
                break;
            }
            case IrOpcode::kChangeUint32ToUint64: {
                Uint32Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt64(static_cast<uint64_t>(m.Value()));
                break;
            }
            case IrOpcode::kTruncateFloat64ToWord32: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt32(DoubleToInt32(m.Value()));
                if (m.IsChangeInt32ToFloat64())
                    return Replace(m.node()->InputAt(0));
                return NoChange();
            }
            case IrOpcode::kTruncateInt64ToInt32: {
                Int64Matcher m(node->InputAt(0));
                if (m.HasValue())
                    return ReplaceInt32(static_cast<int32_t>(m.Value()));
                if (m.IsChangeInt32ToInt64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kTruncateFloat64ToFloat32: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue()) {
                    if (!allow_signalling_nan_ && /*std::*/isnan(m.Value())) {
                        // Do some calculation to make guarantee the value is a quiet NaN.
                        return ReplaceFloat32(DoubleToFloat32(m.Value() + m.Value()));
                    }
                    return ReplaceFloat32(DoubleToFloat32(m.Value()));
                }
                if (allow_signalling_nan_ && m.IsChangeFloat32ToFloat64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kRoundFloat64ToInt32: {
                Float64Matcher m(node->InputAt(0));
                if (m.HasValue()) {
                    return ReplaceInt32(DoubleToInt32(m.Value()));
                }
                if (m.IsChangeInt32ToFloat64())
                    return Replace(m.node()->InputAt(0));
                break;
            }
            case IrOpcode::kFloat64InsertLowWord32:
                return ReduceFloat64InsertLowWord32(node);
            case IrOpcode::kFloat64InsertHighWord32:
                return ReduceFloat64InsertHighWord32(node);
            case IrOpcode::kStore:
            case IrOpcode::kUnalignedStore:
                return ReduceStore(node);
            case IrOpcode::kFloat64Equal:
            case IrOpcode::kFloat64LessThan:
            case IrOpcode::kFloat64LessThanOrEqual:
                return ReduceFloat64Compare(node);
            case IrOpcode::kFloat64RoundDown:
                return ReduceFloat64RoundDown(node);
            case IrOpcode::kBitcastTaggedToWord: {
                NodeMatcher m(node->InputAt(0));
                if (m.IsBitcastWordToTaggedSigned()) {
                    RelaxEffectsAndControls(node);
                    return Replace(m.InputAt(0));
                }
                break;
            }
            default:
                break;
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt32Add(Node* node)
        {
            DCHECK_EQ(IrOpcode::kInt32Add, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x + 0 => x
            if (m.IsFoldable()) { // K + K => K
                return ReplaceInt32(
                    base::AddWithWraparound(m.left().Value(), m.right().Value()));
            }
            if (m.left().IsInt32Sub()) {
                Int32BinopMatcher mleft(m.left().node());
                if (mleft.left().Is(0)) { // (0 - x) + y => y - x
                    node->ReplaceInput(0, m.right().node());
                    node->ReplaceInput(1, mleft.right().node());
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                    Reduction const reduction = ReduceInt32Sub(node);
                    return reduction.Changed() ? reduction : Changed(node);
                }
            }
            if (m.right().IsInt32Sub()) {
                Int32BinopMatcher mright(m.right().node());
                if (mright.left().Is(0)) { // y + (0 - x) => y - x
                    node->ReplaceInput(1, mright.right().node());
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                    Reduction const reduction = ReduceInt32Sub(node);
                    return reduction.Changed() ? reduction : Changed(node);
                }
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt64Add(Node* node)
        {
            DCHECK_EQ(IrOpcode::kInt64Add, node->opcode());
            Int64BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x + 0 => 0
            if (m.IsFoldable()) {
                return ReplaceInt64(
                    base::AddWithWraparound(m.left().Value(), m.right().Value()));
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt32Sub(Node* node)
        {
            DCHECK_EQ(IrOpcode::kInt32Sub, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x - 0 => x
            if (m.IsFoldable()) { // K - K => K
                return ReplaceInt32(
                    base::SubWithWraparound(m.left().Value(), m.right().Value()));
            }
            if (m.LeftEqualsRight())
                return ReplaceInt32(0); // x - x => 0
            if (m.right().HasValue()) { // x - K => x + -K
                node->ReplaceInput(
                    1, Int32Constant(base::NegateWithWraparound(m.right().Value())));
                NodeProperties::ChangeOp(node, machine()->Int32Add());
                Reduction const reduction = ReduceInt32Add(node);
                return reduction.Changed() ? reduction : Changed(node);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt64Sub(Node* node)
        {
            DCHECK_EQ(IrOpcode::kInt64Sub, node->opcode());
            Int64BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x - 0 => x
            if (m.IsFoldable()) { // K - K => K
                return ReplaceInt64(
                    base::SubWithWraparound(m.left().Value(), m.right().Value()));
            }
            if (m.LeftEqualsRight())
                return Replace(Int64Constant(0)); // x - x => 0
            if (m.right().HasValue()) { // x - K => x + -K
                node->ReplaceInput(
                    1, Int64Constant(base::NegateWithWraparound(m.right().Value())));
                NodeProperties::ChangeOp(node, machine()->Int64Add());
                Reduction const reduction = ReduceInt64Add(node);
                return reduction.Changed() ? reduction : Changed(node);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt32Div(Node* node)
        {
            Int32BinopMatcher m(node);
            if (m.left().Is(0))
                return Replace(m.left().node()); // 0 / x => 0
            if (m.right().Is(0))
                return Replace(m.right().node()); // x / 0 => 0
            if (m.right().Is(1))
                return Replace(m.left().node()); // x / 1 => x
            if (m.IsFoldable()) { // K / K => K
                return ReplaceInt32(
                    base::bits::SignedDiv32(m.left().Value(), m.right().Value()));
            }
            if (m.LeftEqualsRight()) { // x / x => x != 0
                Node* const zero = Int32Constant(0);
                return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero));
            }
            if (m.right().Is(-1)) { // x / -1 => 0 - x
                node->ReplaceInput(0, Int32Constant(0));
                node->ReplaceInput(1, m.left().node());
                node->TrimInputCount(2);
                NodeProperties::ChangeOp(node, machine()->Int32Sub());
                return Changed(node);
            }
            if (m.right().HasValue()) {
                int32_t const divisor = m.right().Value();
                Node* const dividend = m.left().node();
                Node* quotient = dividend;
                if (base::bits::IsPowerOfTwo(Abs(divisor))) {
                    uint32_t const shift = WhichPowerOf2(Abs(divisor));
                    DCHECK_NE(0u, shift);
                    if (shift > 1) {
                        quotient = Word32Sar(quotient, 31);
                    }
                    quotient = Int32Add(Word32Shr(quotient, 32u - shift), dividend);
                    quotient = Word32Sar(quotient, shift);
                } else {
                    quotient = Int32Div(quotient, Abs(divisor));
                }
                if (divisor < 0) {
                    node->ReplaceInput(0, Int32Constant(0));
                    node->ReplaceInput(1, quotient);
                    node->TrimInputCount(2);
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                    return Changed(node);
                }
                return Replace(quotient);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceUint32Div(Node* node)
        {
            Uint32BinopMatcher m(node);
            if (m.left().Is(0))
                return Replace(m.left().node()); // 0 / x => 0
            if (m.right().Is(0))
                return Replace(m.right().node()); // x / 0 => 0
            if (m.right().Is(1))
                return Replace(m.left().node()); // x / 1 => x
            if (m.IsFoldable()) { // K / K => K
                return ReplaceUint32(
                    base::bits::UnsignedDiv32(m.left().Value(), m.right().Value()));
            }
            if (m.LeftEqualsRight()) { // x / x => x != 0
                Node* const zero = Int32Constant(0);
                return Replace(Word32Equal(Word32Equal(m.left().node(), zero), zero));
            }
            if (m.right().HasValue()) {
                Node* const dividend = m.left().node();
                uint32_t const divisor = m.right().Value();
                if (base::bits::IsPowerOfTwo(divisor)) { // x / 2^n => x >> n
                    node->ReplaceInput(1, Uint32Constant(WhichPowerOf2(m.right().Value())));
                    node->TrimInputCount(2);
                    NodeProperties::ChangeOp(node, machine()->Word32Shr());
                    return Changed(node);
                } else {
                    return Replace(Uint32Div(dividend, divisor));
                }
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceInt32Mod(Node* node)
        {
            Int32BinopMatcher m(node);
            if (m.left().Is(0))
                return Replace(m.left().node()); // 0 % x  => 0
            if (m.right().Is(0))
                return Replace(m.right().node()); // x % 0  => 0
            if (m.right().Is(1))
                return ReplaceInt32(0); // x % 1  => 0
            if (m.right().Is(-1))
                return ReplaceInt32(0); // x % -1 => 0
            if (m.LeftEqualsRight())
                return ReplaceInt32(0); // x % x  => 0
            if (m.IsFoldable()) { // K % K => K
                return ReplaceInt32(
                    base::bits::SignedMod32(m.left().Value(), m.right().Value()));
            }
            if (m.right().HasValue()) {
                Node* const dividend = m.left().node();
                uint32_t const divisor = Abs(m.right().Value());
                if (base::bits::IsPowerOfTwo(divisor)) {
                    uint32_t const mask = divisor - 1;
                    Node* const zero = Int32Constant(0);
                    Diamond d(graph(), common(),
                        graph()->NewNode(machine()->Int32LessThan(), dividend, zero),
                        BranchHint::kFalse);
                    return Replace(
                        d.Phi(MachineRepresentation::kWord32,
                            Int32Sub(zero, Word32And(Int32Sub(zero, dividend), mask)),
                            Word32And(dividend, mask)));
                } else {
                    Node* quotient = Int32Div(dividend, divisor);
                    DCHECK_EQ(dividend, node->InputAt(0));
                    node->ReplaceInput(1, Int32Mul(quotient, Int32Constant(divisor)));
                    node->TrimInputCount(2);
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                }
                return Changed(node);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceUint32Mod(Node* node)
        {
            Uint32BinopMatcher m(node);
            if (m.left().Is(0))
                return Replace(m.left().node()); // 0 % x => 0
            if (m.right().Is(0))
                return Replace(m.right().node()); // x % 0 => 0
            if (m.right().Is(1))
                return ReplaceUint32(0); // x % 1 => 0
            if (m.LeftEqualsRight())
                return ReplaceInt32(0); // x % x  => 0
            if (m.IsFoldable()) { // K % K => K
                return ReplaceUint32(
                    base::bits::UnsignedMod32(m.left().Value(), m.right().Value()));
            }
            if (m.right().HasValue()) {
                Node* const dividend = m.left().node();
                uint32_t const divisor = m.right().Value();
                if (base::bits::IsPowerOfTwo(divisor)) { // x % 2^n => x & 2^n-1
                    node->ReplaceInput(1, Uint32Constant(m.right().Value() - 1));
                    node->TrimInputCount(2);
                    NodeProperties::ChangeOp(node, machine()->Word32And());
                } else {
                    Node* quotient = Uint32Div(dividend, divisor);
                    DCHECK_EQ(dividend, node->InputAt(0));
                    node->ReplaceInput(1, Int32Mul(quotient, Uint32Constant(divisor)));
                    node->TrimInputCount(2);
                    NodeProperties::ChangeOp(node, machine()->Int32Sub());
                }
                return Changed(node);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceStore(Node* node)
        {
            NodeMatcher nm(node);
            MachineRepresentation rep;
            int value_input;
            if (nm.IsStore()) {
                rep = StoreRepresentationOf(node->op()).representation();
                value_input = 2;
            } else {
                DCHECK(nm.IsUnalignedStore());
                rep = UnalignedStoreRepresentationOf(node->op());
                value_input = 2;
            }

            Node* const value = node->InputAt(value_input);

            switch (value->opcode()) {
            case IrOpcode::kWord32And: {
                Uint32BinopMatcher m(value);
                if (m.right().HasValue() && ((rep == MachineRepresentation::kWord8 && (m.right().Value() & 0xFF) == 0xFF) || (rep == MachineRepresentation::kWord16 && (m.right().Value() & 0xFFFF) == 0xFFFF))) {
                    node->ReplaceInput(value_input, m.left().node());
                    return Changed(node);
                }
                break;
            }
            case IrOpcode::kWord32Sar: {
                Int32BinopMatcher m(value);
                if (m.left().IsWord32Shl() && ((rep == MachineRepresentation::kWord8 && m.right().IsInRange(1, 24)) || (rep == MachineRepresentation::kWord16 && m.right().IsInRange(1, 16)))) {
                    Int32BinopMatcher mleft(m.left().node());
                    if (mleft.right().Is(m.right().Value())) {
                        node->ReplaceInput(value_input, mleft.left().node());
                        return Changed(node);
                    }
                }
                break;
            }
            default:
                break;
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceProjection(size_t index, Node* node)
        {
            switch (node->opcode()) {
            case IrOpcode::kInt32AddWithOverflow: {
                DCHECK(index == 0 || index == 1);
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) {
                    int32_t val;
                    bool ovf = base::bits::SignedAddOverflow32(m.left().Value(),
                        m.right().Value(), &val);
                    return ReplaceInt32(index == 0 ? val : ovf);
                }
                if (m.right().Is(0)) {
                    return Replace(index == 0 ? m.left().node() : m.right().node());
                }
                break;
            }
            case IrOpcode::kInt32SubWithOverflow: {
                DCHECK(index == 0 || index == 1);
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) {
                    int32_t val;
                    bool ovf = base::bits::SignedSubOverflow32(m.left().Value(),
                        m.right().Value(), &val);
                    return ReplaceInt32(index == 0 ? val : ovf);
                }
                if (m.right().Is(0)) {
                    return Replace(index == 0 ? m.left().node() : m.right().node());
                }
                break;
            }
            case IrOpcode::kInt32MulWithOverflow: {
                DCHECK(index == 0 || index == 1);
                Int32BinopMatcher m(node);
                if (m.IsFoldable()) {
                    int32_t val;
                    bool ovf = base::bits::SignedMulOverflow32(m.left().Value(),
                        m.right().Value(), &val);
                    return ReplaceInt32(index == 0 ? val : ovf);
                }
                if (m.right().Is(0)) {
                    return Replace(m.right().node());
                }
                if (m.right().Is(1)) {
                    return index == 0 ? Replace(m.left().node()) : ReplaceInt32(0);
                }
                break;
            }
            default:
                break;
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceWord32Shifts(Node* node)
        {
            DCHECK((node->opcode() == IrOpcode::kWord32Shl) || (node->opcode() == IrOpcode::kWord32Shr) || (node->opcode() == IrOpcode::kWord32Sar));
            if (machine()->Word32ShiftIsSafe()) {
                // Remove the explicit 'and' with 0x1F if the shift provided by the machine
                // instruction matches that required by JavaScript.
                Int32BinopMatcher m(node);
                if (m.right().IsWord32And()) {
                    Int32BinopMatcher mright(m.right().node());
                    if (mright.right().Is(0x1F)) {
                        node->ReplaceInput(1, mright.left().node());
                        return Changed(node);
                    }
                }
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceWord32Shl(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord32Shl, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x << 0 => x
            if (m.IsFoldable()) { // K << K => K
                return ReplaceInt32(
                    base::ShlWithWraparound(m.left().Value(), m.right().Value()));
            }
            if (m.right().IsInRange(1, 31)) {
                // (x >>> K) << K => x & ~(2^K - 1)
                // (x >> K) << K => x & ~(2^K - 1)
                if (m.left().IsWord32Sar() || m.left().IsWord32Shr()) {
                    Int32BinopMatcher mleft(m.left().node());
                    if (mleft.right().Is(m.right().Value())) {
                        node->ReplaceInput(0, mleft.left().node());
                        node->ReplaceInput(1,
                            Uint32Constant(~((1U << m.right().Value()) - 1U)));
                        NodeProperties::ChangeOp(node, machine()->Word32And());
                        Reduction reduction = ReduceWord32And(node);
                        return reduction.Changed() ? reduction : Changed(node);
                    }
                }
            }
            return ReduceWord32Shifts(node);
        }

        Reduction MachineOperatorReducer::ReduceWord64Shl(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord64Shl, node->opcode());
            Int64BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x << 0 => x
            if (m.IsFoldable()) { // K << K => K
                return ReplaceInt64(
                    base::ShlWithWraparound(m.left().Value(), m.right().Value()));
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceWord32Shr(Node* node)
        {
            Uint32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x >>> 0 => x
            if (m.IsFoldable()) { // K >>> K => K
                return ReplaceInt32(m.left().Value() >> (m.right().Value() & 31));
            }
            if (m.left().IsWord32And() && m.right().HasValue()) {
                Uint32BinopMatcher mleft(m.left().node());
                if (mleft.right().HasValue()) {
                    uint32_t shift = m.right().Value() & 31;
                    uint32_t mask = mleft.right().Value();
                    if ((mask >> shift) == 0) {
                        // (m >>> s) == 0 implies ((x & m) >>> s) == 0
                        return ReplaceInt32(0);
                    }
                }
            }
            return ReduceWord32Shifts(node);
        }

        Reduction MachineOperatorReducer::ReduceWord64Shr(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord64Shr, node->opcode());
            Uint64BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x >>> 0 => x
            if (m.IsFoldable()) { // K >> K => K
                return ReplaceInt64(m.left().Value() >> (m.right().Value() & 63));
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceWord32Sar(Node* node)
        {
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x >> 0 => x
            if (m.IsFoldable()) { // K >> K => K
                return ReplaceInt32(m.left().Value() >> (m.right().Value() & 31));
            }
            if (m.left().IsWord32Shl()) {
                Int32BinopMatcher mleft(m.left().node());
                if (mleft.left().IsComparison()) {
                    if (m.right().Is(31) && mleft.right().Is(31)) {
                        // Comparison << 31 >> 31 => 0 - Comparison
                        node->ReplaceInput(0, Int32Constant(0));
                        node->ReplaceInput(1, mleft.left().node());
                        NodeProperties::ChangeOp(node, machine()->Int32Sub());
                        Reduction const reduction = ReduceInt32Sub(node);
                        return reduction.Changed() ? reduction : Changed(node);
                    }
                } else if (mleft.left().IsLoad()) {
                    LoadRepresentation const rep = LoadRepresentationOf(mleft.left().node()->op());
                    if (m.right().Is(24) && mleft.right().Is(24) && rep == MachineType::Int8()) {
                        // Load[kMachInt8] << 24 >> 24 => Load[kMachInt8]
                        return Replace(mleft.left().node());
                    }
                    if (m.right().Is(16) && mleft.right().Is(16) && rep == MachineType::Int16()) {
                        // Load[kMachInt16] << 16 >> 16 => Load[kMachInt8]
                        return Replace(mleft.left().node());
                    }
                }
            }
            return ReduceWord32Shifts(node);
        }

        Reduction MachineOperatorReducer::ReduceWord64Sar(Node* node)
        {
            Int64BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x >> 0 => x
            if (m.IsFoldable()) {
                return ReplaceInt64(m.left().Value() >> (m.right().Value() & 63));
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceWord32And(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord32And, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.right().node()); // x & 0  => 0
            if (m.right().Is(-1))
                return Replace(m.left().node()); // x & -1 => x
            if (m.left().IsComparison() && m.right().Is(1)) { // CMP & 1 => CMP
                return Replace(m.left().node());
            }
            if (m.IsFoldable()) { // K & K  => K
                return ReplaceInt32(m.left().Value() & m.right().Value());
            }
            if (m.LeftEqualsRight())
                return Replace(m.left().node()); // x & x => x
            if (m.left().IsWord32And() && m.right().HasValue()) {
                Int32BinopMatcher mleft(m.left().node());
                if (mleft.right().HasValue()) { // (x & K) & K => x & K
                    node->ReplaceInput(0, mleft.left().node());
                    node->ReplaceInput(
                        1, Int32Constant(m.right().Value() & mleft.right().Value()));
                    Reduction const reduction = ReduceWord32And(node);
                    return reduction.Changed() ? reduction : Changed(node);
                }
            }
            if (m.right().IsNegativePowerOf2()) {
                int32_t const mask = m.right().Value();
                int32_t const neg_mask = base::NegateWithWraparound(mask);
                if (m.left().IsWord32Shl()) {
                    Uint32BinopMatcher mleft(m.left().node());
                    if (mleft.right().HasValue() && (mleft.right().Value() & 0x1F) >= base::bits::CountTrailingZeros(mask)) {
                        // (x << L) & (-1 << K) => x << L iff L >= K
                        return Replace(mleft.node());
                    }
                } else if (m.left().IsInt32Add()) {
                    Int32BinopMatcher mleft(m.left().node());
                    if (mleft.right().HasValue() && (mleft.right().Value() & mask) == mleft.right().Value()) {
                        // (x + (K << L)) & (-1 << L) => (x & (-1 << L)) + (K << L)
                        node->ReplaceInput(0, Word32And(mleft.left().node(), m.right().node()));
                        node->ReplaceInput(1, mleft.right().node());
                        NodeProperties::ChangeOp(node, machine()->Int32Add());
                        Reduction const reduction = ReduceInt32Add(node);
                        return reduction.Changed() ? reduction : Changed(node);
                    }
                    if (mleft.left().IsInt32Mul()) {
                        Int32BinopMatcher mleftleft(mleft.left().node());
                        if (mleftleft.right().IsMultipleOf(neg_mask)) {
                            // (y * (K << L) + x) & (-1 << L) => (x & (-1 << L)) + y * (K << L)
                            node->ReplaceInput(0,
                                Word32And(mleft.right().node(), m.right().node()));
                            node->ReplaceInput(1, mleftleft.node());
                            NodeProperties::ChangeOp(node, machine()->Int32Add());
                            Reduction const reduction = ReduceInt32Add(node);
                            return reduction.Changed() ? reduction : Changed(node);
                        }
                    }
                    if (mleft.right().IsInt32Mul()) {
                        Int32BinopMatcher mleftright(mleft.right().node());
                        if (mleftright.right().IsMultipleOf(neg_mask)) {
                            // (x + y * (K << L)) & (-1 << L) => (x & (-1 << L)) + y * (K << L)
                            node->ReplaceInput(0,
                                Word32And(mleft.left().node(), m.right().node()));
                            node->ReplaceInput(1, mleftright.node());
                            NodeProperties::ChangeOp(node, machine()->Int32Add());
                            Reduction const reduction = ReduceInt32Add(node);
                            return reduction.Changed() ? reduction : Changed(node);
                        }
                    }
                    if (mleft.left().IsWord32Shl()) {
                        Int32BinopMatcher mleftleft(mleft.left().node());
                        if (mleftleft.right().Is(base::bits::CountTrailingZeros(mask))) {
                            // (y << L + x) & (-1 << L) => (x & (-1 << L)) + y << L
                            node->ReplaceInput(0,
                                Word32And(mleft.right().node(), m.right().node()));
                            node->ReplaceInput(1, mleftleft.node());
                            NodeProperties::ChangeOp(node, machine()->Int32Add());
                            Reduction const reduction = ReduceInt32Add(node);
                            return reduction.Changed() ? reduction : Changed(node);
                        }
                    }
                    if (mleft.right().IsWord32Shl()) {
                        Int32BinopMatcher mleftright(mleft.right().node());
                        if (mleftright.right().Is(base::bits::CountTrailingZeros(mask))) {
                            // (x + y << L) & (-1 << L) => (x & (-1 << L)) + y << L
                            node->ReplaceInput(0,
                                Word32And(mleft.left().node(), m.right().node()));
                            node->ReplaceInput(1, mleftright.node());
                            NodeProperties::ChangeOp(node, machine()->Int32Add());
                            Reduction const reduction = ReduceInt32Add(node);
                            return reduction.Changed() ? reduction : Changed(node);
                        }
                    }
                } else if (m.left().IsInt32Mul()) {
                    Int32BinopMatcher mleft(m.left().node());
                    if (mleft.right().IsMultipleOf(neg_mask)) {
                        // (x * (K << L)) & (-1 << L) => x * (K << L)
                        return Replace(mleft.node());
                    }
                }
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::TryMatchWord32Ror(Node* node)
        {
            DCHECK(IrOpcode::kWord32Or == node->opcode() || IrOpcode::kWord32Xor == node->opcode());
            Int32BinopMatcher m(node);
            Node* shl = nullptr;
            Node* shr = nullptr;
            // Recognize rotation, we are matching:
            //  * x << y | x >>> (32 - y) => x ror (32 - y), i.e  x rol y
            //  * x << (32 - y) | x >>> y => x ror y
            //  * x << y ^ x >>> (32 - y) => x ror (32 - y), i.e. x rol y
            //  * x << (32 - y) ^ x >>> y => x ror y
            // as well as their commuted form.
            if (m.left().IsWord32Shl() && m.right().IsWord32Shr()) {
                shl = m.left().node();
                shr = m.right().node();
            } else if (m.left().IsWord32Shr() && m.right().IsWord32Shl()) {
                shl = m.right().node();
                shr = m.left().node();
            } else {
                return NoChange();
            }

            Int32BinopMatcher mshl(shl);
            Int32BinopMatcher mshr(shr);
            if (mshl.left().node() != mshr.left().node())
                return NoChange();

            if (mshl.right().HasValue() && mshr.right().HasValue()) {
                // Case where y is a constant.
                if (mshl.right().Value() + mshr.right().Value() != 32)
                    return NoChange();
            } else {
                Node* sub = nullptr;
                Node* y = nullptr;
                if (mshl.right().IsInt32Sub()) {
                    sub = mshl.right().node();
                    y = mshr.right().node();
                } else if (mshr.right().IsInt32Sub()) {
                    sub = mshr.right().node();
                    y = mshl.right().node();
                } else {
                    return NoChange();
                }

                Int32BinopMatcher msub(sub);
                if (!msub.left().Is(32) || msub.right().node() != y)
                    return NoChange();
            }

            node->ReplaceInput(0, mshl.left().node());
            node->ReplaceInput(1, mshr.right().node());
            NodeProperties::ChangeOp(node, machine()->Word32Ror());
            return Changed(node);
        }

        Reduction MachineOperatorReducer::ReduceWord32Or(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord32Or, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x | 0  => x
            if (m.right().Is(-1))
                return Replace(m.right().node()); // x | -1 => -1
            if (m.IsFoldable()) { // K | K  => K
                return ReplaceInt32(m.left().Value() | m.right().Value());
            }
            if (m.LeftEqualsRight())
                return Replace(m.left().node()); // x | x => x

            return TryMatchWord32Ror(node);
        }

        Reduction MachineOperatorReducer::ReduceWord32Xor(Node* node)
        {
            DCHECK_EQ(IrOpcode::kWord32Xor, node->opcode());
            Int32BinopMatcher m(node);
            if (m.right().Is(0))
                return Replace(m.left().node()); // x ^ 0 => x
            if (m.IsFoldable()) { // K ^ K => K
                return ReplaceInt32(m.left().Value() ^ m.right().Value());
            }
            if (m.LeftEqualsRight())
                return ReplaceInt32(0); // x ^ x => 0
            if (m.left().IsWord32Xor() && m.right().Is(-1)) {
                Int32BinopMatcher mleft(m.left().node());
                if (mleft.right().Is(-1)) { // (x ^ -1) ^ -1 => x
                    return Replace(mleft.left().node());
                }
            }

            return TryMatchWord32Ror(node);
        }

        Reduction MachineOperatorReducer::ReduceFloat64InsertLowWord32(Node* node)
        {
            DCHECK_EQ(IrOpcode::kFloat64InsertLowWord32, node->opcode());
            Float64Matcher mlhs(node->InputAt(0));
            Uint32Matcher mrhs(node->InputAt(1));
            if (mlhs.HasValue() && mrhs.HasValue()) {
                return ReplaceFloat64(bit_cast<double>(
                    (bit_cast<uint64_t>(mlhs.Value()) & uint64_t { 0xFFFFFFFF00000000 }) | mrhs.Value()));
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceFloat64InsertHighWord32(Node* node)
        {
            DCHECK_EQ(IrOpcode::kFloat64InsertHighWord32, node->opcode());
            Float64Matcher mlhs(node->InputAt(0));
            Uint32Matcher mrhs(node->InputAt(1));
            if (mlhs.HasValue() && mrhs.HasValue()) {
                return ReplaceFloat64(bit_cast<double>(
                    (bit_cast<uint64_t>(mlhs.Value()) & uint64_t { 0xFFFFFFFF }) | (static_cast<uint64_t>(mrhs.Value()) << 32)));
            }
            return NoChange();
        }

        namespace {

            bool IsFloat64RepresentableAsFloat32(const Float64Matcher& m)
            {
                if (m.HasValue()) {
                    double v = m.Value();
                    return DoubleToFloat32(v) == v;
                }
                return false;
            }

        } // namespace

        Reduction MachineOperatorReducer::ReduceFloat64Compare(Node* node)
        {
            DCHECK(IrOpcode::kFloat64Equal == node->opcode() || IrOpcode::kFloat64LessThan == node->opcode() || IrOpcode::kFloat64LessThanOrEqual == node->opcode());
            Float64BinopMatcher m(node);
            if (m.IsFoldable()) {
                switch (node->opcode()) {
                case IrOpcode::kFloat64Equal:
                    return ReplaceBool(m.left().Value() == m.right().Value());
                case IrOpcode::kFloat64LessThan:
                    return ReplaceBool(m.left().Value() < m.right().Value());
                case IrOpcode::kFloat64LessThanOrEqual:
                    return ReplaceBool(m.left().Value() <= m.right().Value());
                default:
                    UNREACHABLE();
                }
            } else if ((m.left().IsChangeFloat32ToFloat64() && m.right().IsChangeFloat32ToFloat64()) || (m.left().IsChangeFloat32ToFloat64() && IsFloat64RepresentableAsFloat32(m.right())) || (IsFloat64RepresentableAsFloat32(m.left()) && m.right().IsChangeFloat32ToFloat64())) {
                // As all Float32 values have an exact representation in Float64, comparing
                // two Float64 values both converted from Float32 is equivalent to comparing
                // the original Float32s, so we can ignore the conversions. We can also
                // reduce comparisons of converted Float64 values against constants that
                // can be represented exactly as Float32.
                switch (node->opcode()) {
                case IrOpcode::kFloat64Equal:
                    NodeProperties::ChangeOp(node, machine()->Float32Equal());
                    break;
                case IrOpcode::kFloat64LessThan:
                    NodeProperties::ChangeOp(node, machine()->Float32LessThan());
                    break;
                case IrOpcode::kFloat64LessThanOrEqual:
                    NodeProperties::ChangeOp(node, machine()->Float32LessThanOrEqual());
                    break;
                default:
                    UNREACHABLE();
                }
                node->ReplaceInput(
                    0, m.left().HasValue() ? Float32Constant(static_cast<float>(m.left().Value())) : m.left().InputAt(0));
                node->ReplaceInput(
                    1, m.right().HasValue() ? Float32Constant(static_cast<float>(m.right().Value())) : m.right().InputAt(0));
                return Changed(node);
            }
            return NoChange();
        }

        Reduction MachineOperatorReducer::ReduceFloat64RoundDown(Node* node)
        {
            DCHECK_EQ(IrOpcode::kFloat64RoundDown, node->opcode());
            Float64Matcher m(node->InputAt(0));
            if (m.HasValue()) {
                return ReplaceFloat64(std::floor(m.Value()));
            }
            return NoChange();
        }

        CommonOperatorBuilder* MachineOperatorReducer::common() const
        {
            return mcgraph()->common();
        }

        MachineOperatorBuilder* MachineOperatorReducer::machine() const
        {
            return mcgraph()->machine();
        }

        Graph* MachineOperatorReducer::graph() const { return mcgraph()->graph(); }

    } // namespace compiler
} // namespace internal
} // namespace v8
